[R-sig-Debian] problem with `viridis` on Ubuntu 20.04

[Samuele Carcagno]

Il 30/04/20 03:39, Dirk Eddelbuettel ha scritto:
> 
> On 30 April 2020 at 03:26, Samuele Carcagno wrote:
> | I'm not familiar with the internals of `viridisLite`, so I'm not sure
> | I'd be able to help there. I could open a bug report on the
> | `viridisLite` repo and see if the author has suggestions on how to
> | narrow down the issue.
> 
> It would help if someone running Ubuntu 20.04 could reproduce.
> 

after some further investigation I found out that the issue was related 
to some calls to the `solve` function in `make.rgb`, and indeed running 
`example(solve)` would hang my R session. After I changed the default 
BLAS with:

sudo update-alternatives --config libblas.so.3-x86_64-linux-gnu

the problem disappeared. The BLAS output of `sessionInfo` now that 
`solve` is working is:

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.9.0
LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/liblapack.so.3

while before when `solve` was not working it was:

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3
LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/liblapack.so.3

so it seems the issue is with the Ubuntu package `libopenblas0-pthread` 
and has nothing to do with R. I don't know why openblas-pthread was the 
default BLAS on my system.

Thank you for your help.

Best,

Sam